This invention relates to a brake system for a rolling carriage. More particularly, this invention relates to a baby walker equipped with a safety brake system for reacting to the presence of a ledge and inhibiting rolling movement of the baby walker on an underlying surface with respect to the ledge to help prevent the baby walker from rolling over the ledge.
Young children left unattended in conventional baby walkers are frequently injured in stairway and tip-over accidents. Oftentimes, a curious youngster will propel the baby walker right up to the top edge of a staircase, porch, patio, sidewall, or the like. Further movement of the baby carriage past the edge at the urging of the youngster can tip the entire baby walker over the edge causing the seated youngster to fall down the stairway or the like with the baby walker and suffer unwanted injury.
A rolling carriage or baby walker equipped with a safety brake system for automatically inhibiting movement of such rolling carriages and walker significantly past a drop-off boundary edge of the underlying floor without requiring supervision or intervention by another person would aid in preventing dangerous tip-over situations and otherwise avoid shortcomings of known rolling carriages and walkers.
In accordance with the present invention, an improved carriage includes a load-receiving surface supported on a base, rolling means for rollably supporting the base on an underlying surface, and means for movably coupling the rolling means to the base. The rolling means and coupling means cooperate to lower an effective portion of the base to a collapsed position in frictional engagement with the underlying surface whenever a portion of the rolling means moves over a boundary edge of the underlying surface to at least a predetermined distance below the plane of the underlying surface. In this collapsed position, movement of the base with respect to the boundary edge is inhibited to aid in preventing tip-over movement of the carriage completely over the boundary edge.
In preferred embodiments of the present invention, the carriage includes at least three rolling units pivotally coupled to a base in spaced relation about the circumference or periphery of the base. For example, the base could be of hexagonal shape. A pair of wheels is mounted in spaced-apart relation on each rolling unit to straddle the pivot axis of the rolling unit and to roll freely on the underlying surface. A high friction pad is mounted on the base and presented toward the underlying surface for frictional engagement therewith.
In operation, movement of any one of the wheels over a boundary edge of the underlying surface to a point at least a predetermined distance below the plane of the underlying surface causes the rolling unit supporting such wheel to pivot from a normally horizontal rolling position to a pivoted position. Such pivoting movement acts to lower the high friction pad or other elongated section of the base into frictional engagement with the underlying surface and lower the carriage. In addition, alarm means is desirably provided for indicating engagement of the high friction pad and the underlying surface following collapse of the carriage to alert nearby persons of such collapse by means of an audible signal.
The automatic braking feature provided by the collapsible carriage of the present invention advantageously provides means for detecting and reacting to the presence of a ledge and substantially inhibiting movement of an unsupervised carriage over the ledge. While the best mode of the invention known to the inventor involves a brake system for baby walkers, it is expected that such a feature has broader application, e.g., blocking movement of carriages or the like operated by visually-impaired persons or other handicapped persons generally unable to detect or react to the presence of drop-off ledges or the like.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.